[gmac]

I made a German Pilsner a couple weeks ago and overshot my gravity by about 0.012. I didn't have anymore distilled water at the time and couldn't get any so I fermented as it was. It's now finished and I'd like to add 2 gals of water to it in order to bring the volume up and alcohol down. It is currently about 13.5 gals.

Should I boil, cool and carbonate the water first and then rack the beer onto the water in the keg or can I just add boiled, cooled water directly to the fermenter?  I'm not that worried about O2 because the fermenter has a lot of CO2 in it still and I'm going to be pouring in through the CO2. I am even considering just adding distilled direct from the jug because I doubt that there are many bacteria in commercially prepared distilled water either.

My target was a 5% beer and I'm at about 6.5 right now. 

Thanks.

[dkfick]

If you're going to add water post fermentation it's important you get as much oxygen out of it as possible.  I don't think you will actually get it all out just by boiling... I would probably just leave it at it's current vol and gravity...

[troybinso]

I think boiling it will get out the oxygen. I would boil, cool and add to the fermenter.

[HoosierBrew]

If you're going to add water post fermentation it's important you get as much oxygen out of it as possible.  I don't think you will actually get it all out just by boiling... I would probably just leave it at it's current vol and gravity...

+1. Hop character would diminish pretty noticeably too in a hop forward style like German Pils, aside from oxidation risks.

[dkfick]

I think boiling it will get out the oxygen. I would boil, cool and add to the fermenter.

I dunno from things i've been seeing I don't think it removes it all... and I have to imagine there would be more o2 left in the water after boiling and sitting out to cool than you might pick up during racking to secondary (which a lot of people don't want to do the extra rack due to oxidation concerns).  To me it's just asking for trouble if you do it after fermentation... Seems like maybe you would be ok if you added some sugars to it and kicked fermentation back up...

http://www.newton.dep.anl.gov/askasci/chem07/chem07025.htm

[dak0415]

How about this.  Boil the water, adding a couple of tbs sugar.  Transfer HOT into a corny and cool under CO2, then push under pressure into the fermentor and wait for the yeasties to do their thing. 
Why do we not worry about oxidation when bottling for bottle conditioning?

[Joe Sr.]

How about this.  Boil the water, adding a couple of tbs sugar.  Transfer HOT into a corny and cool under CO2, then push under pressure into the fermentor and wait for the yeasties to do their thing. 
Why do we not worry about oxidation when bottling for bottle conditioning?

I would be very concerned about what happens to the corny when the HOT water cools in a sealed environment.  My guess is the corny would crush inwards.  So I wouldn't suggest this.

As far as bottle conditioning, when the yeast eats the priming sugar they are also scavenging oxygen.  At least that's my understanding.  Of course, you still want to minimize the O2 in the beer when you bottle and O2 caps are cheap enough for insurance.

[HoosierBrew]

FWIW, one of my first AG batches was a German Pils, and I overshot my OG by ~ that much. It ended up at ~ 6% abv.  IIRC I lagered it longer than normal (maybe more like 8 weeks instead of 6), and aside from obviously being over on OG, I remember enjoying it quite a bit.

[dkfick]

How about this.  Boil the water, adding a couple of tbs sugar.  Transfer HOT into a corny and cool under CO2, then push under pressure into the fermentor and wait for the yeasties to do their thing. 
Why do we not worry about oxidation when bottling for bottle conditioning?

I worry about oxidation when bottling and bottle conditioning... caps leak small amounts of o2 and this is why beers have a shelf life and still oxidize in the bottle ;-)

I think your idea could work since you add the additional sugar to it which should kick up fermentation again in the beer (to prevent oxidation... could have effects on flavor of the pilsner though...).  I wouldn't be too worried about the corny keg imploding though.  I mean they are made to withstand 120psi of pressure.  I use my vacuum pump on mine all the time without issue... FYI I have no clue on how hard of a vacuum the cooling wort could create.

[troybinso]

I think boiling it will get out the oxygen. I would boil, cool and add to the fermenter.

I dunno from things i've been seeing I don't think it removes it all... and I have to imagine there would be more o2 left in the water after boiling and sitting out to cool than you might pick up during racking to secondary (which a lot of people don't want to do the extra rack due to oxidation concerns).  To me it's just asking for trouble if you do it after fermentation... Seems like maybe you would be ok if you added some sugars to it and kicked fermentation back up...

http://www.newton.dep.anl.gov/askasci/chem07/chem07025.htm

It will take a while for the oxygen to be reabsorbed into the water after boiling. If you run the hot water through a counterflow wort chiller then it will cool down quickly and can be considered very low in oxygen. If you add this to your femeneter, then you can expect the yeast to take up any oxygen that does make it in there during fermentation. Ideally this is all done before fermentation, but it can work post-fermentation as well.

This is a common practice in mega-breweries, and some not so mega-breweries. You brew to a higher than intended gravity and then water it down in the fermenter. It allows you to get more beer out of a smaller brewhouse. I guess the difference here is that the water down part wasn't planned for in the first place, and doing so may ended giving you a "watered down" version of  the beer you have.

Another option is to boil and cool the water, then carbonate it and add it to the finished beer.

[dkfick]

I believe when the larger breweries do this (ab-inbev) they use vacuum distilled water.

When you add the water in post fermentation you're adding oxygen if all you have done is boiled it.. even if you could instantly cool it and absorb 0 oxygen in the process and introduce that boiled chilled water to the beer you would still be introducing oxygen because boiling alone does not remove all the oxygen.

I dunno.  I just think you're asking for oxidation and/or acetaldehyde.

[klickitat jim]

According to Brew Strong High Gravity show, Mike McDole does this. But he dilutes just the amount he plans to serve within a day or two to avoid oxidation

[erockrph]

+1. Hop character would diminish pretty noticeably too in a hop forward style like German Pils, aside from oxidation risks.

^^^ This. Your IBU's are probably already a little under your target given the higher wort gravity. I wouldn't want to dilute that any further. In cases where beer is intentionally diluted post-fermentation, the original beer is brewed with the correct IBU's/hopping rate to account for this. Otherwise, you're just watering-down your beer and it will likely taste that way.

You're more likely to screw up a decent beer than improve it when you start trying to "fix" things post-fermentation, IMO.

[beersk]

I think I'd leave it. It's strong, but if it tastes good, don't mess with it.

[euge]

You're more likely to screw up a decent beer than improve it when you start trying to "fix" things post-fermentation, IMO.

+1

I think I'd leave it. It's strong, but if it tastes good, don't mess with it.

++1!